Severe Hypertriglyceridemia in a Patient With Metabolic Syndrome and Psoriasis on Risankizumab-Rzaa

We report a case of severe hypertriglyceridemia (HTG) complicated by hyperviscosity syndrome as a possible adverse reaction to risankizumab-rzaa in a 49-year-old male with a history of longstanding uncontrolled type 2 diabetes, obesity, and coronary artery disease with prior ST-elevation myocardial infarction. On admission, the patient presented with xanthomatous plaques, chest and epigastric discomfort, and headache. Subsequent blood testing revealed severely elevated triglyceride (TG) levels at 7670 mg/dL (86.59 mmol/L) [reference range: <150 mg/dL; 1.69 mmol/L] and total cholesterol at 934 mg/dL (24.14 mmol/L) [reference range: <200 mg/dL; 5.17 mmol/L]. Triglyceride levels decreased and symptoms resolved with dietary restrictions and plasmapheresis. At follow-up, his TG remained elevated but improved, and he was advised to continue lipid-lowering medications as well as cessation of risankizumab. While the patient presented with high risk factors, we posit that the subacute presentation of severe HTG is a possible result of his recent course of risankizumab-rzaa therapy for management of psoriasis. This is noteworthy as pharmaceutical surveys and clinical trials do not list severe HTG as an adverse effect. Postmarketing surveillance studies are essential to confirm this potential association and monitor drug safety. In summary, this case highlights a possible link between risankizumab and severe HTG, emphasizing the importance of ongoing pharmacovigilance to identify and manage unexpected adverse effects associated with new medications.